Planodraph co



T. H. MARTEN.

SHIPS DAVIT.

APPLICATION FILED APR. 6. 1 911. RENEWED JAN. I3, 1919.

1,313,404. 1 PatentedAug. 19,1919.

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IJIVENTOR: MW II III I I III III III Tm: LOLLMBIA PLANOGRAPH cu"WASHINGTON, D. c.

T. H. MARTEN.

SHIPS DAVIT: APPLICATION FILED. APR. 6. 1911. RENEWED JAN. 13,1919.

1 3 13, 4:04: Patented Aug. 19, 1919.

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THE COLUMBIA PLANOGRAPH c0, \vAsmNd'roN, D.

1 UNITED sm'rns s THOMAS-HENRY MAR EN, F YORK, NQYQ sHir 's nAvIT.'

sp ecificati'onbf Letters Pat nt; gw f d A ,-19 1919,

Application fi'led April a 1917; seria1nb.-1se,-21s. Renewed January 13,19191 swarms. 270;945.

To all whovnit='may concern: 1.

a tancewithoutdanger of fouling the-rail of Be it known thatI, THOMASHENRY'MAR- TEN5 a subject ofi the King of GreatBritain, and resident ofthe city and'- State ofNew York, in the United" Statesof America,

have invented certain new and useful lm-I provements iir- Ships" Davits,described in the following specification and illustrated-in theaccompanying drawings,- tl1*a.tifo1*m part of-thesame:

Theprincipal objects of the invention are to -devise a form' of davit'for handling ships boats which may be operated with: ease and theminimumof mechanisln to carry the boat outboard the maximum disthe ship.I

A further objectis to improve that form otd'aviti-il'r which the boomswings in a verticalplane so as to minimize the stress uponthe means forswinging the boom and to reduce the labor of: operating the boom:-

A still further objeot istodev ise arstructnre which will be'v extremelyrigid and which" may be manufactured at Very low cost and whichisadapted-te utilizethead+ vantageous' features of therot'atmg type0fboom with the desirable featnresofrthe vertically swinging boom andfurther to overcome the difiiculties met with in -clear inwthe boat fromthe cheeks.

[any differentforms of mechanically 0p erated da -its have been devisedsome of which swing the boom in a vertical plane and others rotatetheboom 'upon'its longitudinal axis to swing theboatsupporting Theprincipal difficulty ofthe vertical swinging boom is end in a horizontalplane.

that in obtaining the desired outreach the boom head and consequentlythe boat drops considerably in the latter phases of its out ward traveland the frame and operating mechanism required is'cumbersome and eX-pensive and 111* therota'ting type the disadvantage isthat the boomoperates in a transverse plane and has no upward movement to effectthe=lifting of the boat from its rests.

The present inventiona consists essentially in; effecting acombinedvertloal swinging and axially rotating movement oftheboom:

In the 5 accompanying drawings. Figure 1,

is a side elevational view of: a: davit constructed in accordancewiththisinvention 'Fig: s a detail horizontali sect/ion; thro ugh-the=line ab fr"Fig.- 1. a

Fig. 4 is a side elevational view on; a"

modified formaofsdavi-t and! Fig.5. isan end elevational.view..

Reterringto the dr-awings the frame 1 is a rlgld cast structureiofirectangnlariform' having the-cross web 2 extending: between the end:standands and. 4" intermediate oftheir 'height,. said. standards;having; horizontalzjour-nals 5 and: 6 adj acentto the: top

in which the screw spindle l' is jounnaled'.

'A- bar. 8 is rigidly securedbetweenrtheupper ends ot the% standards in:parallel': ar-

rangement with the" spindle 7 and forms a guide for the? .crossheadwhich is in: the form of a sleeve": encircling said 'bair. The

crosshe'ad' '9 l is": formedwith:v a downwardly extending lugfibl which:is; threaded upon thel spindlefl so: that upon: the rotation of the Spin(116131116 CROSShGHdLWillt be caused to travelon the'gnidea. a A131V0tp111 12; rigid withuthercrosshead9 extends lateral 1y from; oneside thereof and v v mu ppglfts a sleeve' lg which" iseprovided with a:projecting. lug 14 through which said pin extends:-

The davitn boom= 15= is slidablyi' and rota tably held intermediate ofits length in the sleeve 13 i and the lower end lfiiiSirotatably steppedin a cup 17 pivotallyri'mountediat the baseof the frame andadaptedtoswing in a vertical plane;

Thecross web 2 of the frame --is formed with aquadrantal: toothedi rack18 011: the! side adjacent to the boom; said rack: being.

concentric" tothe pivotal center; of: ther cup-1'71 A sleeve- 19,keyeda-or' otherwiserigidly seeured upon the boom 15 below the sleevev13 is formed with a toothed segn ient' 2O: which I meshes with the teethof the rack. 18 sotha t asthe boomeswings in a verticalplane it will becaused to rotate on its longitudinal axis. A web 21 is preferably castintegral with the rack teeth 18 at the upper and swings the boom ina'vertical plane.- Coincident with'the outboard swing .ofthe from nju y,l h 1 l v p The boom 15 is formed with a curved upper end 22 and is ofthe axially rotating side to strengthen and protect the teeth typehaving a suitable'eye 23 at the upper end to receive the shackle of theupper block of the boat falls.

The boom is preferably set upper end is turned laterally over the boatandpreferably pointing inboard. Upon the rotation of the spindle 7 bymeans of the crank24: the crosshead 9 is moved outwardly boompost in avertical plane the said post is rotated axially: through the engagementof the toothed segment of the sleeve 19 with the rack 18 therebyswinging the curved upper end of the boom in an outboard direc ti'on; WV

The pivot support of the lower end of the boom is preferably arrangedabout midway of the inboardand' outboard positions of angular-ity ofthe-boom.

In the operation of this vdavit, the vertical swinging movement from aninboard inclination and the first part of the transverse swing of-theouter end of the boom causes thesaid 'outerend of the boom to travel inan upward and outward curve thereby taking up any slack in the falls andlifting the boat clear of the chocks. The continued I double swingingmovement carries the boat outboard in a path closely approximating thehorizontal being. first raised slightly then towardthe-outer positionlowered slightly, the path being slightly curved and the highest pointin the movement being when-the boat is clearing the rail of the ship.

The movement is very positive and extremely simple and iowing to therotative movement the vertical swing required to obtain themaximumfreach is Very short.

Consequently the screw spindle is short and a slow pitch thread may beused. This enables the operation to be effected with the minimum:application of power upon the operating crank.

The short .throw i of the boom postallows so that in the extreme inboardposition the post slopes inboard; in a vertical plane and the curved:

invention which is to effect this axial rota- [tion coincident with thevertical 'pivotal movement.

A modified form of the device is shown in Figs; 4 and 5 in which thepost of the curved boom 15 is rotata'bly mounted upon a bracket 25pivotally secured to the ships deck so as toswing in a verticalplane.The bracket 25 is supported and operated in its swinging movement tomove the boom in a vertical plane by an adjustable strut 26 pivotallyconnected at one end to the said bracket 25 and at the other endto arigid bracket 27.

The coincident axial rotation of the boom is eflected by meansof an arm28 rigidly secured to theboom post and a link 29 is pivotally connectedatone end to the outer end of said arm and at the other end to the rigidbracket 27. As the boom swings outwardly in the vertical plane the link29 pulls upon the arm 28v and rotates the boom post.

NVhat I claim as myinvention is 1. A boat davit comprising a rigid framesecured to the deck, a boom pivotally and rotatably mounted in the baseof said frame and adapted to swing in a vertical plane from an inwardlyinclined to an outwardly inclined position and to rotate axially, andmeans for eflecting an axial rotation of the boom coincident with theswinging movement.

2. A boat davit comprising a rigid frame secured to the deck, a boom.pivotally and rotatably mounted inthe base of said frame and adapted toswing in a vertical plane and to rotate axially, means slidablysupported on said frame engaging said boom intermediate, of its lengthand supporting it against foreand aft stresses, means for operating saidslidable member in said frame, and means for effecting an axial rotationof the boom coincident with the swinging movement.

3. A boat davit comprising a rigid frame secured to the, deck, a boompivotallyand rotatably mounted in the base of said frame and adaptedtoswing in a vertical plane and to rotate axially, a crosshead slidablyarranged on said frame, a sleeve pivotally con nected to said crossheadand slidably encircling the boom, a screw spindle journaled in the frameand operating said crosshead, and means for effecting an axial rotationof the boom coincidentvwith the swinging move.- ment.

4:. A boat davit comprising a rigid frame secured to the deck, a boompivotally and rotatably mounted in the base of said frame and adapted toswing in a vertical plane and to rotate axially, means slidablysupported on said frame engaging said boom intermediate of its lengthand supporting it against fore and aft stresses, means for operatingsaid slidable member in said frame,

a toothed rack arranged on the side of said frame, and a toothed gearsecured to said boom and meshing With said rack.

5. In a boat davit, in combination a rigid unitary cast metal framehaving a segmental gear rack arranged on one side intermediate of itsheight, a bar crosshead guide-secured in the top of said frame, acrosshead slidably arranged on said bar, a' screw spindle arranged belowsaid guide and operating said crosshead, a socket member pivotallysupported in the base of the frame, a boom stepped in said socketmember, a sleeve rota- THOMAS HENRY MARTEN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

